A sign in front of a church in Florida last week said: “Are you sure of your election?”

Translation: You were sure that Mitt Romney would be elected president. Can you be so sure that you will be elected for heaven?

It turns out that part of the political polarization afflicting the nation entails widely divergent perceptions of reality. A wide swath of America was certain that Romney would be elected, and millions were astonished when he lost. Much has been said of the way our fragmented news media have abetted the trend toward fragmented perceptions of the world. The world of conservative commentators seems to have become an echo chamber echoing propaganda and unavailing hope rather than reality.

Liberals on the other hand eased their worries during the election season by poring over the data that showed President Obama would probably win. An official from the Bush administration had famously sneered at the “reality-based” community, suggesting that in the new era reality would be whatever conservatives said it was. This year reality got its revenge.

Astonished Republicans have grasped at a range of explanations for their failures. They say they had a weak candidate at the head of the ticket. They say the Obama machine was better organized. Both of these assertions are true, but they let the Republican Party off the hook. After all, who nominated Romney?

Other Republicans blame the American people. They point out that President Obama benefited because the people in the cities supported him. If prairie dogs could vote, the Republicans would be in good shape, but the cities are where the people are. By blaming people in the cities, of course, Republicans are conveying a racial message.

Some go further, purveying outright racial paranoia. That is what the Republican chairman in Maine did when he suggested that hundreds of previously unknown black people had shown up at the polls in Maine. Where exactly did this happen? He didn’t know.

A related Republican critique comes from Romney himself. It is the 47 percent theory, which he disavowed during the election but which he repeated afterward. Basically, Romney and other Republicans believe that the Democrats win votes by buying them with public benefits. Franklin Roosevelt was subject to the same criticism because of his support for Social Security, jobs programs and union rights.

It is likely that Romney accuses Democrats of voting out of self-interest because he believes that is what voting is about. After all, no one has accused the business elite that supported Romney of neglecting its own self-interest.

But if politics is going to regain respect in the eyes of the American people, it is important to recognize that there are arguments to be made that involve more than self-interest. Providing health coverage to Americans who lack it is not merely an appeal to the self-interest of those who are likely to benefit; it is a step toward enhancing the health and prosperity of the nation. A similar public interest argument holds for public education and for the security of the aged.

There is a public interest argument for the Republican side, as well. Republicans argue that keeping taxes low is good for the economy as a whole, spreading prosperity more widely. But if it’s possible to defend tax breaks for the rich on the basis of the public interest, it’s also possible to disagree in the public interest. After all, the good of the whole suffers when revenues are too low to support essential services.

Many middle-class white male Americans voted for Obama, not because he would do good things for their specific demographic group, but because they believed he would do good things for the nation. They were offended by Republican views on immigration and women’s rights, not because these issues affected them directly, but because they believed the Republican position would be damaging to the nation. People of all the diverse groups that supported Obama shared that idea.

Now that Republicans and Democrats are back in Washington, charged with resolving our daunting fiscal problems, it is important for them to remember they are there not for the interest of any particular group, but for the good of the nation.